I have a one dollar bill with the letter x at the end of the serial number. what does it mean?

Question

I have a one dollar bill with the letter x at the end of the serial number. what does it mean?

Answer 1

That only means that particular Federal Reserve branch bank printed enough notes to get that far in the alphabet. For Series 1999, the Boston and San Francisco Federal Reserve bank branches issued enough $1 bills that they both got to suffix letter Y.

The other responder is referring to Star notes, which are the notes used for replacing notes damaged during the printing process. The serial number ends with a star in place of a letter.

Answer 2

I think I remember that they were bills that were used to replace a bill that had an error on it during the inspection process. They were supposed to be removed before the bills were released for circulation.  If the bank sees it I believe it will be removed from circulation.